Door-alarm.



No. 746,196. PATENTED DEC. '8, 1903. A. R. STRAHAN.

DOOR ALARM.

, APPLICATION FILED APB.10, 190s. 7

K0 MODEL.

w w if Hiiiiim. v i', E

mix 5555s.- (R ggENTOR. i V v I, O W W 7 BY 0.

6 y. 7 7 I I ATTORNEY.

V Patented December 8, 1903.

PATENT OFFICE.

ARTHUR R. STRAHAN, OF NEW YORK, N. Y.

DOOR-ALARM.

SPECIFICATION forming part of Letters Patent N 0. 746,196, dated December 8, 1903.

Application filed April 10, 1903.- Serial No. 151,994. (No model.)

. To all whom it may concern:

. Be it known that I, ARTHUR R. STRAHAN,

tions and arrangements of parts and peculiarities of construction and operation, all of which will be hereinafter first fully described and then pointed out in the claims.

In the accompanying drawings, forming a [part hereof, Figure 1 is a front elevation of a door-alarm embodying my invention. Fig. 2 is a side elevation thereof. Fig. 3 is a top plan view with the gong removed, illustrating the alarm as in use with a door.

Similar numerals of reference wherever they occur indicate corresponding parts in all the figures.

1 is a frame wherein are mounted a springactuated train of gear-wheels of any approved construction.

2 is the key-post for winding the spring.

3 is the escapement fixed upon a shaft 4.

5 is an arm upon the shaft 4, and 6 is a le- .ver pivoted upon the frame 1 at 7 and having a manipulating handle 8 and extension '9, whereby the escapement and connected parts may be held against movement when desired.

10 is a rod fixed in the shaft4 and bearing a ham mer-head 11, designed to strike a gong 12 when the mechanism is in motion.

13 is a horizontal bar crossing the frame 1 and bearing a pivot 14, whereon is held a cam 15, having a low part 16 and two'high parts 17 and 18. Forming a part of or secured to the cam 15 is an arm 17, to which is pivoted an extension 20, so constructed as to turn the cam 15 when pushed from the rear, but permit an object, such as a door 21, to turn the extension back upon the pivot without moving the cam when closing or shutting.

22 is a spring which normally holds the extension in the position shown in full lines in the drawings. 1

23 is a stop for limiting the backward movement of the cam 15.

24 is a cover for the wheel-train, and 25 repsents ears for'securing the device to a support.

I have shown my alarm as in usewith a door 21; but it is obvious it may be used with a window, transom, 86G.

. In operation the parts are ticularly illustrated in Fig. 3 of the drawings, the high portion 18 of the cam 15 pressing against the hammer-rod 10 preventing the action of the escapement and consequent vibration of the hammer. opened, the cam and connected parts will assume the positions indicated by dotted lines, turning the low portion'1 6 of the cam next to the hammer-rod, releasing the escapement, and sounding the gong. This action will be continued until the cam is set to its initial position or turned, as indicated in dotted lines, to the front of the mechanism, bringing the high part 17 of thecam against the hammerrod, holding it'against further movement. If it is desired to permit the free opening of the doorwithout sounding the alarm, the cam and connected arm are turned, as above described. When the door is open and the cam and arm 20 in the position shown in Fig. 3, the door may be closed without moving the cam, as the extension will turn backward upon its pivot sufficiently to permit such closing.

Having now fully described my invention,

what I claim as new therein, and desire to secure by Letters Patent, is-

1. A door alarm in which is comprised a movement provided with an escapement-shaft bearing a hammer-arm, a gong with which the said hammer may contact, a cam pivoted upon the movementframe and having a low part, two high parts and a horizontal arm arranged to be engaged by the door, one of the said high parts of the cam being arranged to arrest the movement of the hammer when the arm of the cam is in position to be engaged by the door, and the other high part being arranged to engage with the hammer-arm when the cam is turned into inoperative position, and the low part of the cam being between the said high parts, substantially as set forth.

located as par- Should the door be Q 746,196 a g 2. A door-alarm in which is comprised a movement provided with an escapement-shaft bearing a hammer-arm; a gong with which said hammer may contact; a horizontal cam havinga 10w part and a high part, and a projecting, actuating-arm, consisting of two parts pivotaliy united and arranged to permit the door to be closed when the said arm is in operative position without turning the cam, but to cause a movement of the cam when the doo'ris :0 opened, the whole combined and arranged to operate substantially as shown and described.

ARTHUR R. STRAHAN. Witnesses:

TESSIE HAUSER, A. M. PIERCE. 

